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authorGravatarGravatar AJR <ajrhacker@users.noreply.github.com>2017-12-10 15:32:24 -0500
committerGravatarGravatar AJR <ajrhacker@users.noreply.github.com>2017-12-10 15:32:24 -0500
commite733af5b0807dbf88ad32645f4c39210de99946c (patch) (github)
treec180b292e77ba120c08a16210a517782b4faf3eb
parent0306e6e11996495b5c0d5195dbbbac596bf9a78f (diff)
downloadmame-e733af5b0807dbf88ad32645f4c39210de99946c.tar.bz2
mame-e733af5b0807dbf88ad32645f4c39210de99946c.zip
Documentation update (nw)
-rw-r--r--docs/source/techspecs/device_rom_interface.rst16
1 files changed, 15 insertions, 1 deletions
diff --git a/docs/source/techspecs/device_rom_interface.rst b/docs/source/techspecs/device_rom_interface.rst
index ab5eb18737b..8baf7fbb576 100644
--- a/docs/source/techspecs/device_rom_interface.rst
+++ b/docs/source/techspecs/device_rom_interface.rst
@@ -41,7 +41,16 @@ rom description for the system, it will be automatically picked up as
the connected rom. An address map has priority over the region if
present in the machine config.
-| void **set_rom**\ (const void \*base, UINT32 size);
+| void **set_rom_endianness**\ (endianness_t endian)
+| void **set_rom_data_width**\ (u8 width)
+| void **set_rom_addr_width**\ (u8 width)
+
+These methods, intended for generic devices with indefinite hardware
+specifications, override the endianness, data bus width and address
+bus width assigned through the constructor. They must be called from
+within the device before **config_complete** time.
+
+| void **set_rom**\ (const void \*base, u32 size);
At any time post- **interface_pre_start**, a memory block can be
setup as the connected rom with that method. It overrides any
@@ -76,3 +85,8 @@ Using that interface makes the device derive from
**device_memory_interface**. If the device wants to actually use the
memory interface for itself, remember that AS_0/AS_PROGRAM is used by
the rom interface, and don't forget to upcall **memory_space_config**.
+
+For devices which have outputs that can be used to address ROMs but
+only to forward the data to another device for processing, it may be
+helpful to disable the interface when it is not required. This can be
+done by overriding **memory_space_config** to return an empty vector.